JP3112196B2 - Synthetic resin film composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin film composition prepared by blending specific calcium carbonate particles, and is intended for polyolefins, polyesters, etc. having excellent abrasion resistance and transparency. To provide a synthetic resin film composition of the invention.

[0002]

2. Description of the Related Art Synthetic resins are widely used for various industrial purposes. Among them, industrially produced polyester,
Especially polyethylene terephthalate (hereinafter abbreviated as PET)
Has excellent physical and chemical properties and is widely used as fibers, films and other molded articles. For example, in the film field, it is used for magnetic tapes such as audio tapes and video tapes, for capacitors, for photography, for packaging, for OHP, and the like.

[0003] In a polyester film, its slipperiness and abrasion resistance are major factors that determine the workability of the film manufacturing process and the working process in each application and the quality of the product quality. When these slipperiness and abrasion resistance are insufficient, for example, when a magnetic layer is applied to the polyester film surface and used as a magnetic tape, the friction between the coating roll and the film surface during application of the magnetic layer is severe. Wear on the film surface is severe, wrinkles on the film surface in extreme cases,
Scratches occur. Also, even after slitting the film after applying the magnetic layer and processing it into audio, video, computer tape, etc., many guide parts, playback heads, etc., when pulling out from reels or cassettes, winding up and other operations Abrasion occurs significantly, and scratches, distortion occurs, and as a result of precipitation of a white powdery substance due to abrasion of the polyester film surface, a lack of a magnetic recording signal,
That is, it often causes a large dropout.

Conventionally, as a method of reducing the friction coefficient of polyester, inorganic fine particles such as calcium carbonate, titanium dioxide, kaolin, silica, and alumina are contained in polyester to give fine and appropriate irregularities on the surface of a molded product. Many methods have been proposed to improve the surface lubricity of molded articles, but the affinity between the fine particles and the polyester is not sufficient, and neither the transparency nor the abrasion resistance of the film is satisfactory. Polyolefins as well as polyesters are widely used as industrial products for various uses, and biaxially oriented polyolefin films such as polypropylene films are most widely used as various packaging materials. As is well known, this type of polyolefin film is susceptible to blocking due to its tackiness, which not only impairs workability in the production of the film and further higher-order processing thereof, but also, for example, in the use of the film for packaging. In the case of packaging, troubles such as poor opening of the bag are likely to occur. Therefore, this type of film is usually subjected to anti-blocking treatment, fine powdered silica, zeolite, calcium carbonate, or kaolin clay is typically known as an anti-blocking agent,
And used. Although excellent transparency is required as a quality characteristic of the polyolefin film, this transparency and blocking resistance are inconsistent quality characteristics, and a large amount of polyolefin film is required to improve the blocking resistance. When an antiblocking agent is used, the transparency of the polyolefin film decreases with an increase in the amount of the antiblocking agent, and these modifying additives can effectively satisfy both the antiblocking property and the transparency. However, conventional inorganic powders have disadvantages.

As described above, a wide variety of inorganic particles are used as an anti-blocking agent in a synthetic resin film. Among them, calcium carbonate is available at a low cost because limestone as a raw material is abundantly produced in Japan. It is used for synthetic resin films for various applications, because it is relatively easy to control particle morphology and particle diameter as compared with other inorganic particles. However, when the conventionally used calcium carbonate particles are used as an anti-blocking agent, the calcium carbonate particles do not have a good affinity with the synthetic resin, so that the surface of the calcium carbonate particles blended in the synthetic resin film may be damaged. Means that large voids (air layers) are present. As a result, for example, in a polyester film, calcium carbonate particles in the film easily fall off in the form of white powder, and a good film can be obtained as a material for magnetic tape. Did not. Similarly, also in the polyolefin film, the large voids present on the surface of the calcium carbonate particles as an antiblocking agent tend to greatly impair the transparency of the film, and a polyolefin film having both blocking resistance and transparency is obtained. I couldn't.

[0006] Conventionally, in order to improve the lack of affinity of the calcium carbonate particles with the synthetic resin, calcium carbonate particles have been prepared by using various surface treatment agents according to the type, field of use, and purpose of use of the target resin. Surface modification of the surface has been proposed, among which fatty acids, fatty acid soaps, resin acids,
Resin acid soap and the like are generally used after surface treatment on the surface of calcium carbonate particles. However, a synthetic resin film is usually stretched in the longitudinal and transverse directions at the time of production in many cases, and voids formed between the surface of the calcium carbonate particles in the film and the resin portion are formed during stretching of the film. Therefore, in order to reduce the number of voids and the size of voids, a sufficient affinity between the calcium carbonate surface and the resin is required. A synthetic resin film using calcium carbonate particles whose surface was treated with a treating agent as an antiblocking agent could not be said to be sufficiently excellent in abrasion resistance and transparency.

On the other hand, silicate compound particles such as silica, which have been widely used as a calcium carbonate particle as an anti-blocking agent for a synthetic resin film in the past, have a great difference in affinity for the synthetic resin from calcium carbonate particles. Although there is no, since the hydroxyl groups are present on the surface of the silicate compound particles, it is easy to modify the surface with an organic silane coupling agent, and the affinity with the synthetic resin by the silane coupling agent treatment. Many have been reported to be able to improve significantly. For example, JP-A-63-31345 provides a polyester composition using a synthetic silica treated with an organic silane coupling agent as a blocking inhibitor.

[0008] In the case of calcium carbonate particles, if this organic silane-based coupling agent can be surface-treated on the particle surface, a sufficient affinity with a synthetic resin can be expected, and the calcium carbonate particles have a synergistic effect with the inherent properties of calcium carbonate. It is expected that an unprecedented good antiblocking agent will be prepared,
Due to the chemical structure of calcium carbonate, the surface of the calcium carbonate particles has no hydroxyl group that can chemically bond with the organic silane coupling agent present on the surface of the silicate compound particles. Surface treatment with a system coupling agent has been considered impossible. In order to solve this problem, a method of treating an organic silane compound after previously modifying the surface of calcium carbonate particles with an inorganic material having a hydroxyl group such as silica hydrosol as disclosed in JP-A-52-30852 has been attempted. ing. However, in this method, it is difficult to uniformly treat the silica hydrosol on the surface of the calcium carbonate particles, and the calcium carbonate particles are easily aggregated. Even if the organic silane compound is treated, calcium carbonate containing large aggregates is present. Particles, and good calcium carbonate particles cannot be obtained as an anti-blocking agent for a synthetic resin film. Therefore, even if such calcium carbonate particles are used as an anti-blocking agent, the synthetic resin has excellent abrasion resistance and transparency. No film is obtained.

[0009]

DISCLOSURE OF THE INVENTION The present invention relates to a synthesis using calcium carbonate particles as a blocking inhibitor, in which an organic silane compound is strongly chemically bonded to the surface of the calcium carbonate particles to significantly improve the affinity with a synthetic resin. An object of the present invention is to provide a resin film composition, thereby providing a synthetic resin film composition of a polyolefin, polyester, or the like, which is excellent in abrasion resistance and transparency, which has not been obtained conventionally.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, the calcium carbonate particles were subjected to surface treatment with an organic material having both -COOH and -OH groups in advance. By performing a two-layer treatment with an organic silane compound, an organic substance having both —COOH groups and —OH groups is chemically fixed to the surface of the calcium carbonate particles, and the —OH groups are treated with an organic silane compound. To form a chemical bond with the compound, we found that the organic silane compound can be treated firmly on the calcium carbonate particle surface,
It has been found that a synthetic resin film in which a specific amount of calcium carbonate particles treated with the organic silane compound is blended is a film having unprecedented abrasion resistance, transparency, and good sliding properties.

Hereinafter, the present invention will be described in detail. The present invention provides a synthetic resin film composition comprising 0.01 to 3 parts by weight of calcium carbonate particles having an organic substance having a carboxyl group and a hydroxyl group and an organic silane compound adsorbed in this order with respect to 100 parts by weight of the synthetic resin. Things. In the present invention, the organic substance first subjected to the surface treatment on the calcium carbonate surface is an organic substance having both a -COOH group and a -OH group, and the organic substance has a strong binding force to both the surface of the calcium carbonate particles and the organic silane compound. And a substance having a role of bridging between the surface of the calcium carbonate particles and the organic silane compound. The organic substance to be first surface-treated on the surface of the calcium carbonate particles is not particularly limited as long as it is an organic substance having both a -COOH group and an -OH group, and may be an organic substance in any form of a polymer or a monomer. It is effective and one or more of these forms may be used. These organic substances include monomers such as hydroxyphenylstearic acid and hydroxypivalic acid, α, β unsaturated carboxylic acids and hydroxy esters of α, β unsaturated carboxylic acids, and copolymers of vinyl acetate and acrylic acid with alkali. Polymers such as copolymers of polyvinyl alcohol and α, β unsaturated carboxylic acids obtained by saponification of the above can be exemplified, but are not limited to these exemplified organic substances. Further, the -COOH group in these organic substances may be neutralized by an alkali metal, ammonium, an amine, or the like, or may be partially neutralized in a polymer. The surface treatment amount of these organic substances with respect to the calcium carbonate particles is determined by the particle diameter of the calcium carbonate particles, the dispersion state, the type and the treatment amount of the organosilane compound to be treated later, and the like.
The number of OH groups and -OH groups and the ratio of -COOH groups to -OH groups may be determined at any time, but usually 0.01 to 10% by weight, preferably 0.01 to 5% by weight, based on the calcium carbonate particles. More preferably, it is 0.03 to 2% by weight. Examples of the surface treatment method include a wet treatment method in which calcium carbonate particles are directly introduced into water or an organic solvent slurry, and a dry treatment method in which a surface treatment agent is added to dry powder of calcium carbonate particles and vigorously stirred. I can list the methods.

An organic silane compound as a second surface treatment agent for calcium carbonate particles has a general chemical formula of YRSi.
Represented by X _3. X in the above formula is a hydrolyzable group bonded to a silicon atom represented by a chloro group, an alkoxy group, an acetoxy group, etc., and Y is a vinyl group, a methacryl group, an epoxy group, an amino group, or the like. An organic functional group that reacts with a representative organic matrix. Therefore, the organic silane compound used in the present invention is not particularly limited as long as it has at least one hydrolyzable group and at least one non-hydrolyzable organic functional group that reacts with an organic matrix in the molecule. Γ-chloropropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, β- ( 3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-
β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane and the like can be mentioned, and these can be used alone or in combination of two or more. The surface treatment amount of these organic silane compounds with respect to the calcium carbonate particles may be determined at any time according to the particle size of the calcium carbonate particles, the dispersion state, the type and amount of the organic substance previously treated, the type of the synthetic resin, and the like. 0.01 to 10% by weight, preferably 0.05 to 8% by weight, more preferably 0.1 to 10% by weight, based on the particles.
5% by weight. The surface treatment method is a wet treatment method in which the first organic substance is directly charged into water or an organic solvent slurry of the treated calcium carbonate particles, and a surface treatment agent is added to the calcium carbonate particle dry powder and strongly stirred. Such as a dry treatment method. Further, an organic silane compound may be added when the calcium carbonate particles are kneaded with the synthetic resin. For example, calcium carbonate particles surface-treated with an organic material having both -COOH groups and -OH groups may be kneaded with the synthetic resin. When a chip for a synthetic resin film is produced by kneading with the above, an organic silane compound may be added in this kneading step to perform a surface treatment on the calcium carbonate particles.

The surface-treated calcium carbonate particles used in the present invention are prepared as described above. In order to further improve the dispersibility and stability of the surface-treated calcium carbonate particles, fatty acids and resins other than those described above are used. Organic acids such as acid, acrylic acid, oxalic acid and citric acid, tartaric acid, phosphoric acid, condensed phosphoric acid,
An inorganic acid such as hydrofluoric acid, a polymer thereof, a salt thereof, or a surface treating agent such as an ester thereof, a dispersant such as a surfactant, or the like may be used in combination as long as the object of the present invention is not hindered. . The calcium carbonate particles surface-treated by the above method are mainly blended as a blocking inhibitor in a polyester film such as PET and PBT and a polyolefin film such as PP and PE, so that the object of the present invention can be achieved, of course. It is also possible to provide a synthetic resin film having good physical properties, such as polyamide such as nylon 66 and nylon 6, and a halogen-containing polymer such as polyvinyl chloride. The amount of the surface-treated calcium carbonate particles to be added as an anti-blocking agent to the synthetic resin film composition of the present invention is not uniform depending on the use of the film, the type of the synthetic resin, etc. On the other hand, the amount is preferably 0.01 to 3 parts by weight, particularly preferably 0.01 to 1 part by weight. 0.0
If the amount is less than 1 part by weight, the desired amount of the anti-blocking effect is insufficient due to the small amount of addition, and the accuracy of blending with the synthetic resin and uniformly dispersing the compound is reduced, so that it is difficult to obtain a good synthetic resin film. On the other hand, if it exceeds 3 parts by weight, the transparency of the film is impaired, and the blocking resistance is not improved in spite of the added amount, and the stretchability of the film is undesirably reduced.

The crystalline form of calcium carbonate used in the synthetic resin film composition of the present invention is not particularly limited, and may be any of calcite-type calcium carbonate, aragonite-type calcium carbonate, and vaterite-type calcium carbonate. There is no particular limitation on the method for producing calcium carbonate. Heavy calcium carbonate prepared by crushing and classifying limestone on the occasion, synthetic calcium carbonate prepared by a solution method or a carbon dioxide method, or the like may be used. Further, regarding the particle size and dispersibility of calcium carbonate,
Although there is no particular limitation, it is usually preferable to use calcium carbonate having a primary particle diameter of 0.1 μm to 10 μm. In particular, the polyester film serving as the base of the tape used for magnetic recording purposes has the following requirements (A), (A), (C), (D), (E), and (F). More preferred is the use of calcium carbonate. (A) 0.1 μm ≦ DS1 ≦ 10 μm (A) 0.02 μm ≦ DS2 ≦ 10 μm (C) DP3 / DS1 ≦ 1.25 (D) 1.0 ≦ DP2 / DP4 ≦ 2.5 (E) 1.0 ≤ DP1 / DP5 ≤ 4.0 (f) (DP2-DP4) / DP3 ≤ 1.0, where DS1: average particle diameter (μm) of the major axis of the primary particles as determined by a scanning electron microscope (SEM). DS2: average particle diameter (μm) of the short diameter of the primary particles examined by a scanning electron microscope (SEM). DP1: Light transmission type particle size distribution analyzer (SA- manufactured by Shimadzu Corporation)
In the particle size distribution measured using CP3), the particle size (μ
m) DP2: Light transmission type particle size distribution analyzer (SA- manufactured by Shimadzu Corporation)
In the particle size distribution measured using CP3), the particle size (μ
m) DP3: Light transmission type particle size distribution analyzer (SA- manufactured by Shimadzu Corporation)
In the particle size distribution measured using CP3), the particle diameter (μ
m) DP4: Light transmission type particle size distribution analyzer (SA- manufactured by Shimadzu Corporation)
In the particle size distribution measured using CP3), the particle size (μ
m) DP5: Light transmission type particle size distribution analyzer (SA- manufactured by Shimadzu Corporation)
In the particle size distribution measured using CP3), the particle size at 90% of the cumulative weight calculated from the larger particle size side (μ
m)

There is no particular limitation on the shape of the calcium carbonate particles. However, when it is necessary to have both a high running property of the film and an impact resistance against a strong impact on the film, the DS1 is used. And the ratio of DS2 are preferably 0.3 ≦ DS2 / DS1 ≦ 1.0, more preferably 0.5 ≦ DS2 / DS1 ≦ 0.9.

In order to produce a film using the synthetic resin film composition of the present invention, a synthetic resin as a raw material of the film, the above-mentioned surface-treated calcium carbonate, and other additives such as pigments, dyes, ultraviolet rays Absorbents, various stabilizers, antioxidants, sunscreens (eg carbon black,
One or more of various additives such as titanium dioxide), a processing aid, an antistatic agent, and, if necessary, a part of another antiblocking agent is added, and these mixtures are kneaded and melted by a kneading machine, It can be produced by preparing a master chip, melting the master chip again, and then subjecting the chip to a biaxial stretching process by a conventional method. Further, in a polyester film used as a material of a magnetic recording tape, the surface-treated calcium carbonate is in the form of a glycol slurry, before the polymerization reaction of the polyester reaction for producing the polyester, particularly before the end of the transesterification or esterification reaction. The addition method is preferred. The synthetic resin film obtained from the composition of the present invention has various advantages such as excellent slipperiness, and abrasion resistance and transparency compared to conventional synthetic resin films. Available to

[0017]

The present invention will be specifically described below with reference to examples.
The present invention is not limited to only these examples.
Calcium carbonate used in Examples and Comparative Examples was prepared by the following procedure.

Calcium carbonate A While stirring a mixed solution of 20 liters of 1.0 mol / l aqueous sodium carbonate solution and 20 liters of 0.2 mol / l aqueous sodium sulfate solution in a reaction vessel, 0.8 mol / l of chloride was added thereto. 20 liters of an aqueous calcium solution was charged at a charging rate of 0.4 liters per second, and the mixture was stirred to cause a carbonation reaction.
When the pH in the reaction system reaches 11.0, the pH of the reaction system becomes 1
Sodium hydroxide was added to 2.0 and then 5
The reaction was completed by stirring for minutes. The liquid temperatures before and after the reaction were adjusted to 17.2 ° C. and 17.0 ° C., respectively. Thereafter, dehydration was carried out according to a conventional method, and the dehydrated cake was sufficiently washed with ion-exchanged water. Table 1 shows special values relating to the form, dispersity, and particle size of the obtained calcium carbonate. Thereafter, dehydration drying was performed to obtain calcium carbonate A powder. The obtained calcium carbonate A was 100% calcite-type calcium carbonate as a result of X-ray diffraction measurement. As a result of observation by SEM, the particle size was 0.8 to 3 μm.
m of cubic calcium carbonate.

Calcium carbonate B Hydroxypivalic acid equivalent to 0.5% by weight of calcium carbonate is subjected to surface treatment on an aqueous dispersion of calcium carbonate A under stirring, and then 1% by weight of γ- Aminopropyltriethoxysilane was subjected to a surface treatment under stirring conditions, followed by dehydration drying to obtain calcium carbonate B powder.

Calcium carbonate C Calcium carbonate C powder is prepared in the same manner as calcium carbonate B except that hydroxypivalic acid is changed to sodium hydroxyphenylstearate and γ-aminopropyltriethoxysilane is changed to vinyltriethoxysilane. I got a body.

Calcium carbonate D A calcium carbonate D powder was obtained in the same manner as for calcium carbonate B except that hydroxypivalic acid was changed to sodium stearate.

Calcium carbonate E Calcium carbonate E powder was obtained in the same manner as for calcium carbonate B except that γ-aminopropyltriethoxysilane was not treated.

Granular quicklime having a calcium carbonate F activity of 82 (special grade reagent) is pulverized with a dry pulverizer (Coroplex, manufactured by Alpine), and the obtained quicklime powder is poured into methanol and sieved with a 200 mesh sieve. After removing coarse particles using, a methanol suspension of quicklime having a solid concentration of 20% by weight as quicklime was prepared.
The methanol suspension is wet-milled (Dynomill PIL).
(OT type, manufactured by WAB)) to prepare a dispersion of quicklime in a methanol suspension. Methanol is additionally added to the methanol dispersion of quicklime to dilute the quicklime to a concentration of 3.0% by weight. Further, water equivalent to 11 times the mole of quicklime is added, and methanol + quicklime + water is added. Was prepared. After adjusting the mixed system containing 200 g of quicklime to 42 ° C., carbon dioxide gas was passed through the mixed system at a conduction rate of 0.082 mol / mol of quicklime to start the carbonation reaction under stirring. did. Five minutes after the start of the carbonation reaction, the conductivity in the system reached the maximum point, and the temperature in the system at the maximum point was adjusted to 45 ° C. Thereafter, the carbonation reaction was continued. When the electric conductivity in the system reached 100 μS / cm 19 minutes after the start of the carbonation reaction, the supply of carbon dioxide gas was stopped, and the carbonation reaction was stopped. As a result of X-ray diffraction measurement, the obtained calcium carbonate was 100% vaterite type elliptical spherical calcium carbonate. Table 1 shows special values relating to the form, degree of dispersion, and particle size of the obtained calcium carbonate. Ethylene glycol was added to the mixed system of methanol, water and calcium carbonate prepared by the above method to prepare a mixed system of methanol, water, ethylene glycol and calcium carbonate. The mixed system was flushed using a rotary evaporator, and methanol and water were removed from the mixed system to prepare an ethylene glycol slurry of calcium carbonate F. The residual ratio of water in the ethylene glycol was 0.5% by weight, and the solid concentration of calcium carbonate was 20.0%.
% By weight.

Calcium carbonate G A mixed system of methanol, water and calcium carbonate is prepared in the same manner as in the process of preparing calcium carbonate F, and a surface treatment agent (acrylic) equivalent to 1.0% by weight based on calcium carbonate is added to the mixed system. A copolymer in which the weight ratio of each of the acid and the hydroxy acrylate is 40:60, and 50% of all carboxyl groups in the acrylic acid portion are ammonium salts. Glycol was added to prepare a mixed system of methanol, water and calcium carbonate. The mixed system was flushed using a rotary evaporator, and methanol and water were removed from the mixed system to prepare an ethylene glycol slurry. Thereafter, β-
3% by weight of (3,4-epoxycyclohexyl) ethyltrimethoxysilane is added to calcium carbonate in the ethylene glycol slurry, and an organic silane treatment is performed.
An ethylene glycol slurry of calcium carbonate G was obtained.

Example 1 0.16 parts by weight of 2,6-di-t-butyl-p-cresol as an antioxidant was added to 100 parts by weight of a polypropylene resin having a melt flow rate of 1.9 g / 10 minutes, and "Irganox". 1010 (trade name, manufactured by Ciba Geigy) "
0.02 parts by weight, 0.05 parts by weight of calcium stearate as a hydrochloric acid catching agent, and calcium carbonate B were added, mixed with a super mixer, and then pelletized with an extruder. The pellets were formed into a sheet-like film using an extruder, and stretched 5 times in the longitudinal direction and 10 times in the transverse direction to finally obtain a stretched film having a thickness of 30 μm. One surface of the stretched film was subjected to corona discharge treatment. The transparency and blocking resistance of these biaxially stretched films were measured. Film transparency was measured by stacking four films in accordance with ASTM-D-1003. The blocking resistance of the film was set so that the contact area between the ^two films was 10 cm ² , placed between the two glass plates, and placed in a 50 g
/ Cm ^{2 under} a load of 40 ° C. for 7 days, and using a Shopper type tester, pulling speed of 500
The film was peeled off at a rate of mm / min, and the maximum load was read and evaluated. Table 2 shows the results of the film evaluation of this example.

Example 2 A polypropylene film was prepared in the same manner as in Example 1 except that calcium carbonate B was changed to calcium carbonate C, and the physical properties of the film were evaluated in the same manner as in Example 1. Table 2 shows the results of the film evaluation of this example.

Comparative Example 1 A polypropylene film was prepared in the same manner as in Example 1 except that calcium carbonate B was changed to calcium carbonate A, and the physical properties of the film were evaluated in the same manner as in Example 1. Table 2 shows the evaluation results of the films of this comparative example.

Comparative Example 2 A polypropylene film was prepared in the same manner as in Example 1 except that calcium carbonate B was changed to calcium carbonate D, and the physical properties of the film were evaluated in the same manner as in Example 1. Table 2 shows the evaluation results of the films of this comparative example.

Comparative Example 3 A polypropylene film was prepared in the same manner as in Example 1 except that calcium carbonate B was changed to calcium carbonate E, and the physical properties of the film were evaluated in the same manner as in Example 1. Table 2 shows the evaluation results of the films of this comparative example.

Example 3 An ethylene glycol slurry of calcium carbonate G was added before the polyesterification reaction to carry out a polyesterification reaction.
Polyethylene terephthalate having an intrinsic viscosity (orthochlorophenol, 35 ° C.) of 0.62 dl / g containing 0.3% by weight of calcium carbonate G was prepared. The polyethylene terephthalate was dried at 160 ° C., melt-extruded at 290 ° C., and quenched and solidified on a casting drum maintained at 40 ° C. to obtain an unstretched film. Continued
After preheating the unstretched film to 70 ° C. with a heating roller, it was stretched 3.6 times in the machine direction while heating with an infrared heater. Subsequently, the film was stretched 4.0 times in the horizontal direction at a temperature of 90 ° C., and then heat-treated at 200 ° C. to obtain a biaxially oriented film having a thickness of 15 μm. The quality of the film thus obtained was evaluated by the following method, and the results are shown in Table 3.

Film surface roughness (Ra) This is a value defined by JIS-B0601 as a center line average roughness (Ra). In the present invention, a stylus type surface roughness meter (SURFCORDER SF) manufactured by Kosaka Laboratory Co., Ltd. -30C). The measurement conditions and the like are as follows. (a) Probe tip radius: 2 μm (b) Measurement pressure: 30 mg (c) Cut-off: 0.25 mm (d) Measurement length: 0.5 mm (e) Repeat measurement 5 times for the same sample, and determine the largest value Except for one, it represents the average value of the remaining four data.

The coefficient of friction (μk) of the film is measured as follows using the apparatus used in FIG.
In FIG. 1, 1 is an unwinding reel, 2 is a tension controller, 3, 5, 6, 8, 9, and 11 are free rollers, 4 is a tension detector (entrance), and 7 is a stainless steel SUS304 fixing rod (outside). Diameter 5 mm), 10 is a tension detector (exit), 12 is a guide roller, and 13 is a take-up reel. At a temperature of 20 ° C. and a humidity of 60%, a film cut to a width of イ ン チ inch was attached to a fixing rod (surface roughness: 0.3 μm) at an angle θ = (152/18).
0) 200cm / min by contacting with π radian (152 °)
Move (friction) at the speed of. Entrance tension T ₁ is 3
When the tension controller is prepared so as to be 5 g, the exit tension (T ₂ : g) of the film is 90 m.
After traveling, it is detected by an exit tension detector, and a traveling friction coefficient μk is calculated by the following equation. μk = (2.303 / θ) log (T 2 / T 1) = 0.86log (T 2/35)

Evaluation of Friction Property-I A 1/2 inch wide film surface was brought into contact with a stainless steel fixing pin (surface roughness 0.58) having a diameter of 5 mm at an angle of 150 °, and about 15 cm at a speed of 2 m per minute. reciprocating, frictionally (this time, the entry side tension T ₁ and 80 g).
This operation is repeated, and the degree of scratches generated on the friction surface after 60 reciprocal measurements is visually determined. At this time, there are four stages: ◎ for those with almost no occurrence of scratches, △ for those with little scratch generation, × for those with a large number of scratches generated over the entire surface, and △ for the middle of the former two for scratch generation. judge.

Evaluation of frictional property-II The abrasion of the running surface of the film is evaluated using a five-stage mini super calender. The calender is a five-stage calender consisting of a nylon roll and a steel roll. The processing temperature is 80 ° C., the linear pressure applied to the film is 230 kg / cm, and the film speed is 60 m / min. When the running film has traveled a total length of 5000 m, the abrasion property of the film is evaluated by dirt attached to the top roller of the calendar. <Four-step judgment> ◎: Nylon roll dirt completely 全 く: Nylon roll dirt hardly x ×: Nylon roll dirt XX: Nylon roll dirt very much

Comparative Example 4 A polyethylene terephthalate film was prepared in the same manner as in Example 3 except that calcium carbonate G was changed to calcium carbonate F, and the physical properties of the film were evaluated in the same manner as in Example 3. . Table 3 shows the film evaluation results of this comparative example.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

[Table 3]

[0039]

As described above, the composition of the present invention is excellent in slipperiness, as well as in abrasion resistance and transparency.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for measuring a coefficient of friction (μk) of a film.

──────────────────────────────────────────────────続 き Continuation of front page (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 1/00-101/16 C08K 3/00-13/08 C08J 5/18 C09C 1/02

Claims (4)

(57) [Claims] An amount of calcium carbonate particles, in which an organic substance having a carboxyl group and a hydroxyl group and an organic silane compound are adsorbed in this order, is 0.01 to 100 parts by weight of the synthetic resin.
A synthetic resin film composition comprising 3 parts by weight. 2. An adsorption amount of an organic substance having both a carboxyl group and a hydroxyl group is 0.01 to 1 with respect to calcium carbonate particles.
The synthetic resin film composition according to claim 1, which is 0% by weight. 3. The amount of the organic silane compound adsorbed is 0.01 to 10% by weight based on the calcium carbonate particles.
The synthetic resin film composition according to the above. 4. The calcium carbonate particles according to the following formula (A)
The synthetic resin film composition according to claim 1, which satisfies (f). (A) 0.1 μm ≦ DS1 ≦ 10 μm (A) 0.02 μm ≦ DS2 ≦ 10 μm (C) DP3 / DS1 ≦ 1.25 (D) 1.0 ≦ DP2 / DP4 ≦ 2.5 (E) 1.0 ≤DP1 / DP5≤4.0 (f) (DP2-DP4) /DP3≤1.0, where DS1: average particle diameter (μm) of the major diameter of primary particles examined by a scanning electron microscope (SEM). DS2: average particle diameter (μm) of the short diameter of the primary particles examined by a scanning electron microscope (SEM). DP1: Light transmission type particle size distribution analyzer (SA- manufactured by Shimadzu Corporation)
In the particle size distribution measured using CP3), the particle size (μ
m) DP2: Light transmission type particle size distribution analyzer (SA- manufactured by Shimadzu Corporation)
In the particle size distribution measured using CP3), the particle size (μ
m) DP3: Light transmission type particle size distribution analyzer (SA- manufactured by Shimadzu Corporation)
In the particle size distribution measured using CP3), the particle diameter (μ
m) DP4: Light transmission type particle size distribution analyzer (SA- manufactured by Shimadzu Corporation)
In the particle size distribution measured using CP3), the particle size (μ
m) DP5: Light transmission type particle size distribution analyzer (SA- manufactured by Shimadzu Corporation)
In the particle size distribution measured using CP3), the particle size at 90% of the cumulative weight calculated from the larger particle size side (μ
m)